Field of the Invention
The present invention relates to an exhaust gas purifying device for an internal combustion engine.
Related Art
Conventionally, the exhaust gas purifying device provided in the exhaust channel of an internal combustion engine is configured to include a carrier (honeycomb carrier) on which an exhaust gas purifying catalyst is supported, and a tubular case member that houses this carrier. Upon housing the carrier inside the case member, it is important to reliably retain the carrier inside the case member.
In order to reliably retain the carrier inside the case member, it has been known to adopt a configuration that interposes a retaining member called a mat between the case member inner circumferential face and the carrier outer-circumferential face. In the case of adopting this configuration, the retaining member may produce erosion by being exposed to the exhaust flow, and technology for suppressing such erosion has been proposed (for example, refer to Patent Document 1). With the technology published in Patent Document 1, it is said to be possible to suppress the occurrence of erosion by clogging the mesh at the outer circumference of the carrier supporting the catalyst with a clogging material, thereby avoiding the exhaust gas flow impinging on the retaining member provided more to the radially outer side than the carrier.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2015-54305